Assessment of Alcohol Consumption in Outpatients with Non-alcoholic Fatty Liver Disease

Abstract

Title: Is occasional alcohol consumption associated with the presence of liver fibrosis in patients with non-alcoholic fatty liver disease?

Background & Aims: The impact of alcohol consumption on the non-alcoholic fatty liver disease (NAFLD) is controversial. Recent studies have suggested that light to moderate alcohol consumption might be associated with a lower risk of fibrosis progression in NAFLD. This study investigates the association of alcohol consumption with the prevalence of fibrosis in patients with NAFLD confirming the patient´s statement on alcohol intake by determining a set of direct alcohol markers.

Methods: NAFLD patients were prospectively recruited at the outpatient general Hepatology Clinic at the University Medical Hospital Hamburg-Eppendorf between February and August 2018. The alcohol intake was assessed using a questionnaire. To confirm patients´ statements, direct alcohol markers including Phosphatidylethanol (PEth), ethyl glucuronide in the hair (hEtG) and urine (uEtG), carbohydrate-deficient transferrin (CDT), methanol (MeOH) and ethanol (EtOH) were determined. Liver stiffness and Controlled Attenuation Parameter (CAP) were measured using FibroScan.

Results: After informed consent, a total of 88 patients were included in this study. According to patient´s statements and results of alcohol markers patients were classified as lifetime abstinence (LTA, n=18, 20.5%), recent abstinence (RA, n=15, 17%) or occasional drinkers (OD, n=55, 62.5%) with ethanol intake  20 and  30 g EtOH daily in females and males, respectively. The average reported alcohol consumption of OD was low (28g EtOH weekly). In all patients with reported LTA or RA, all direct alcohol markers tested negative, confirming the truth of patients’ statements. In 32.7% (18/55) of the OD; at least one positive direct alcohol marker indicating recent alcohol consumption was found (88.9% (16/18) PEth, 44.4% (8/18) uEtG and 5.6% (1/18) hEtG). There was no statistical difference between patients with LTA, RA or OD concerning the number of patients with IDDM, BMI, or concerning gender, age, CAP, HbA1c, Bilirubin, GOT, GPT, GGT, Creatinine, LDL-cholesterol, and Triglyceride. The median liver stiffness in LTA was significantly higher than in OD (7 (6.4-20.5) vs. 5.95 (4.8-8.1) kPa, p=0.04), while there was no difference between RA and LTA and between RA and OD.

Conclusions: Consumption of alcohol was common in NAFLD patients. Occasional alcohol consumption throughout a lifetime showed no detrimental effect and even appeared to be associated with lower liver stiffness than lifetime alcohol abstinence. Further longitudinal studies are needed to evaluate how moderate alcohol consumption affects NAFLD progression.